1. Voting Advice via Direct Access to the Relevant Data 1
Voting Advice via Direct Access to
the Relevant Data
Maarten Marx
Universiteit van Amsterdam
Politicologen etmaal, Amsterdam, 2011-06-09

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Outline
• Two types of voting advice systems
• Lipschits on the web
• Technical details
• Conclusions and how further?

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2 types of voting advices systems
• Lipschits method (1977–1998)
• Stemwijzer method (on the web, from 1998)
Same users: voters
Same motivation: help voters in making a choice, based on
manifesto data

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Primary goals
Lipschits • quickly find standpoint of party in manifesto on topic X
• easily compare standpoints of parties on topic X
Stemwijzer quickly find which parties best fit the user on a (for all
voters) fixed set of topics

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Secondary goals
Reuse obtained data for scientific research.
Lipschits
• standardize manifestos
• rich list of salient topics for each election
• rich controlled vocabulary
• (Now) excellent training data for creating classifiers
KiesKompas
• positions of parties on several topics
• positions of “the electorate” on these topics

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Differences between Lipschits and Stemwijzer
• One size fits all vs user decides on topics and parties
• Direct vs indirect access to primary sources
• Different input-output behaviour

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Input-output
In Out
Stemwijzer answer to questions ranked list of parties
Kieskompas ” model of user as a party
Lipschits controled vocabulary terms relevant paragraphs for each party
VerkiezingsKijker ” or free search terms ”

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Demo: ’Lipschits on the web’
verkiezingskijker.nl

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History VerkiezingsKijker
TK 2006 UvA-Stemwijzer.
• Eddy Habben Jansen: take Lipschits as inspiration
• Motivation Stemwijzer: add “proof” for party positions from
their manifestos
PS 2007 UvA-Kieskompas. Verkiezingskijker used to facilitate large
amount of party-placements (12 provinces × 10 parties × 36
positions = 4320 placements.
DNPP corpus UvA Bsc thesis: search engine for DNPP manifesto
corpus.
TK 2010 Google

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Technical Details: outline
1. Idea
2. How to do it
3. Main problem
4. Solutions

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Idea verkiezingskijker
• Replicate Lipschits, “Google style”
• Add free keyword search
• Make it scalable, faster to make (and without a Lipschits . . . )

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How to do that?
• Collect manifestos (in time . . . )
• Standardize them into one data format
• Partition each manifesto into meaningful units (paragraphs)
Outcome Basic Google style search engine which returns on each
search term a ranked list of paragraphs
Advanced search restrict to parties

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Main problem: Semantic gap
Voter and manifesto use different terms to talk about the same topic
• different parties use different terms to talk about the same topic
• small amounts of text per retrieval unit make this problem worse
• Recall Problem: system does not retrieve all relevant paragraphs.

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Two solutions to this
Hierarchical controlled vocabulary
• Basically back to Lipschits.
• Burden at the user.
Document expansion
• find related terms (schiphol vliegveld luchthaven vliegtuig . . .
• expand paragraphs: if it contains one term, add all others
• Aim: Improve recall.
• Danger: topic drift (thus more false positives)

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Predicament
With both solutions we seem to be back at Lipschits and need to do
all the work he did . . .

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Our solution: learning from examples
• Stemwijzer created a list of 100 important election topics.
• For each topic, Stemwijzer found 5 highly relevant paragraphs
• From these paragraphs we harvested all overused terms (using
corpus comparison techniques [Rayson, Garside 2000])
• For each topic we took the top k terms
• Quick manual check to remove outliers
• Output: classifier for each topic, and set of expansion terms.

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Conclusion and what next?
• Both systems are complimentary.
• Modern Lipschits system is useful for both makers and users of
stemwijzer-like systems.
• Fine grained classification of manifestos (and alternatives . . . ) is
useful for comparative research (e.g., Breeman-Timmermans,
Louwerse)

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What next/Discussion
• Standardization of controlled vocabularies and development of
high quality gold standard data is desirable
• Soon: Lipschits 1998 available in Excel and as a fully searchable
hyperlinked web-docoment.
• Wish? same for the “Verkiezingsprogramma’s met cd-rom”
(Holsteyn et al) series?
Or is the system by Google sufficient?